Apparatus for making bags



p 1961 L. SLAGEL ETAL 2,999,533

APPARATUS FOR MAKING BAGS Filed May 1, 1959 3 sheets-S gleet 1 INVENTORS. LAMONT SLAGEL BY HARRY A. MEAD Sept. 12, 1961 Filed May 1, 1959 y HARRY A. MEAD INVENTORi LAMONT SLAGEL 3 Sheets-Sheet 2 ATTORNEY Sept. 12, 1961 1.. SLAGEL ETAL 2,999,533

APPARATUS FOR MAKING BAGS Filed May 1, 1959 3 Sheets-Sheet 3 I08 09 Ol HO 3 III Hg. 6. 59 58 I02 4s 25 Hg 7 23 33 7 44 22 ss 52 I32 2| I31 I l7 1 128 F 9 54 I34 4 A B6 I33 l7 INVENTORS. 127 126N215 I29 LAMONT SLAGEL y HARRY A. MEAD ATTORNEY United States Patent 2,999,533 APPARATUS R MAKING BAGS Lamont Slagel, Denver, and Harry A. Mead, Lakewood, Colo., assignors to Dairy Containers, Inc., Denver, Colo., a corporation of Colorado Filed May 1, 1959, Ser. No. 810,470 18 Claims. (Cl. 154-42) This invention relates to apparatus for making bags and more particularly to apparatus for making bags from flexible or pliable, heat scalable material, such as polyethylene or the like.

The apparatus of this invention is particularly adapted to produce bags for milk and the like, constructed in the manner disclosed and claimed in our copending application Serial No. 721,961, filed March 17, 1958. A flexible or pliable heat scalable material, such as polyethylene, may be extruded in tubular form and then flattended to strip form, which strip then may be rolled about a mandrel or the like to form a cylindrical roll of a diameter suitable for handling. The sides of such a strip are, of course, connected together, but the apparatus of this invention may be operated with a strip formed by folding over a flat strip at the center and heat sealing the edges opposite the fold. As disclosed in our aforesaid copending application Serial No. 721,961, a series of such bags may be formed from such a strip, the bags being connected together in the strip but the individual bags being separable from the strip through a transverse series of perforations, which may be cut or torn across the strip. The bottom of each bag may be closed by a transverse heat seal which extends across the strip adjacent the transverse series of perforations, while a portion of the top of the bag may be left unsealed, but provided with a pair of spaced slots providing a flap therebetween to facilitate opening the unsealed portion which may be used as a filling spout. The remainder of the top of the bag may be closed, as by heat sealing, while the filling spout may be disposed at or adjacent either edge of the bag or at the center. In addition, a heat seal may extend longitudinally of the bag, in spaced relation to one edge, with a longitudinal slit or slot in the longitudinal seal so that the portion of the bag between the slit and the edge is adapted to serve as a pouring spout when the end of such portion is cut off, the end of such portion being closed, of course, until cut off.

Among the problems involved in making such bags are provision for a production rate which is fast enough so that the bags may be made economically, coupled with the necessity for forming the desired heat seals at equally spaced intervals along the strip, without sealing the walls of the strip together at any undesired position. Such heat seals may include a transverse heat seal for each bag which will leave a portion of the top of each bag open and one or more longitudinal heat seals for each bag, spaced from the edges of the strip and when more than one is provided for each bag, connected together by an additional transverse heat seal. Also involved is the production of a transverse series of perforations at equally spaced distances along the strip, which are correlated in position with the transverse heat seal, as well as the production of a pair of longitudinal slits at spaced positions along the bag and correlated in position with the transverse heat seals. Further involved is the production of a longitudinal slit or slot in each longitudinal heat seal and correlated in position with the transverse series of perforations.

Among the objects of the present invention are to provide novel apparatus for making bags of flexible or pliable, heat scalable material; to provide such apparatus which is particularly adapted to produce a series of bags connected together in strip form; to provide such apparatus which is particularly adapted to produce heat seals and slits or perforations at predetermined desired positions; to provide such apparatus which will produce the desired heat seals at desired locations with accuracy and speed; to provide such apparatus which will produce a transverse series of slits or perforations at accurately spaced positions along the strip; to provide such apparatus which will produce longitudinal slots or slits at desired spaced positions along the strip with accuracy and speed; and to provide such apparatus which will be effective and efficient in operation and which may be readily constructed.

Additional objects of this invention, together with the novel features thereof, will become apparent from the description which follows, taken in connection with the accompanying drawings, in which:

FIG. 1 is a generally central longitudinal, vertical section of apparatus constructed in accordance with this invention;

FIG. 2 is a top plan view of a portion of a flat tubular strip of flexible or pliable, heat scalable material, produced by the apparatus of FIG. 1 so as to include a series of connected bags;

FIG. 3 is a front elevation of a heat sealing drum, forming a part of the apparatus of FIG. 1;

FIG. 4 is a longitudinal section of the heat sealing drum, taken along line 4-4 of FIG. 3;

FIG. 5 is a front elevation of a slitting roll and associ ated parts by which desired longitudinal slits are produced in the strip and showing also a timing device operated in conjunction therewith;

FIG. 6 is a top plan view of the slitting roll. and as sociated parts of FIG. 5;

FIG. 7 is a front elevation of a pair of rolls between which the strip passes and which are adapted to produce a transverse series of slits or perforations at successive spaced positions along the strip;

FIG. 8 is a partly diagrammatic side elevation, on a reduced scale, of the apparatus of FIG. 1, illustrating particularly the drive arrangement; and

FIG. 9 is a fragmentary side elevation of an alternative discharge portion of the machine of FIG. 1..

As illustrated in FIG. 1, apparatus constructed in accordance with this invention may comprise a frame F, conveniently formed by welding and/or bolting together suitable structural members, such as channels or beams, to support the various parts of the apparatus. In general, the frame F conveniently is provided with two upright sides, which support bearings for a number of shafts on which are mounted rolls, drums and the like, the two sides being connected together by transverse members, such as channels 9 and 9 at the bottom of the frame and channels 10 and 10' at the top of the frame. Adjacent one end of the frame, a feed roll 11 may be mounted, from which a fiat strip S of a flexible or pliable heat sealable material, such as polyethylene, may be fed through the apparatus, while an alternative feed roll 12 may be disposed in a convenient position, such as below roll 11, so that when the roll 11 becomes exhausted, the apparatus may be temporarily stopped and the strip on the alternative roll 12 connected to the final end of the strip on roll 11, as by manual heat sealing or by an adhesive, or by suitable strips of pressure sensitive tape, so that the strip S may be continuously fed through the machine. Adjacent the opposite end of the machine, the completed strip may again be Wound, as in a roll 13, until the diameter thereof reaches a suflicient dimension, whereupon the strip may be severed, such as at the point of connection between the end of the strip leading from the roll 11 to the start of the strip leading from roll 12, and then wound as an alternative roll 14. As will be evident, by the utilization of alternative feed rolls 11 and 1 2, the strip may be fed continuously through the apparatus and it is therefore unnecessary to rethread the strip, through the various parts, each time the feed from the initial roll is changed. Also, due to the use of alternative final rolls 13 and 14, the time during which the machine may be stopped for the purpose of changing over to a diiferent final roll is minimized.

The feed rolls 11 and 12 and the final rolls 13 and 14 may each be mounted on a hub 15, which in turn may be mounted on a shaft 16, 16, 17 or 17 respectively. Each hub may be formed of wood or any other suitable material, While shafts 17 and 17' are rotatable in bearings supported by brackets 18 extending outwardly from an upright portion of frame F, and the bearings for shafts 16 and 16' may be mounted on brackets similar to brackets 18 at the opposite end of the machine. Each of shafts 16, 16', 17 and 17 should be so mounted in the bearings that it may be readily removed from the bearings to permit the hub 15 to be removed from the shaft, when a full roll is to replace an exhaust roll, or vice versa, and for this purpose, conventional open top bearings are suitable.

1 Strip S is pulled through the machine, first passing around a guide roll 20, so that the strip feed will, in effect, originate at the same point whether feeding from roll 11 or roll 12, and then through a series of three straightening rollers 21, 22, and 23, which stretch the strip and thus remove any curvature or set in the strip due to storage in coil or roll form. Each of rolls 20 to 23 is mounted on a separate shaft 24 and is an idler roll, i.e., freely rotatable with the shaft on which it is mounted, each shaft 24 in turn being mounted in bearings supported in any suitable manner at the opposite sides of frame F. From roll 23, the strip passes around a feed roll 25 for a heat sealing drum H, the feed roll normally being sufiiciently large that it is more convenient to form the same as a drum, as shown, and being driven in the direction of the arrow thereon Roll 25 is driven in synchronism with heat sealing drum H, as by a gear 26 mounted at each end of roll 25 and each in engagement with a gear 27 mounted at each end of the heat sealing drum H, as shown in FIGS. 3 'and 4. A shaft 28 for roll 25 may extend at each end into a bearing supported in a suitable manner atop the framework F, as by a bracket 29. A shaft 30 provided with a hub 31 for one end of the heat sealing drum H is preferably driven by a motor or other suitable device, as in a manner described later, while heating drum H is hollow and preferably is filled with a cooling medium, such as as water, which may be introduced into the interior of the drum and exhausted in a manner described later.

The strip S is maintained in contact with the surface of heat sealing drum H, preferably to the extent of at least one half or more of the perpihery of drum H, as by a belt 32 of canvas or other suitable material, a portion of the belt being maintained against strip S by belt stretching rolls 33 and 34, disposed in generally opposite positions in relation to heat sealing drum H, with the remainder of the belt conveniently being maintained as a loop by idler rolls 35 and 36. Each separate shaft 37 for one of rolls 33 to 36 is conveniently supported for free rotation by bearings mounted on the respective sides of frame F. From the heat sealing drum H, the strip S passes around a slitting roll 38, which is mounted on a shaft 39 and is driven in synchronism with the heat sealing drum H, as by a gear 40 disposed at each end of the slitting roll 38 and meshing with the corresponding gear cutting or slitting blades, such as arm 41 provided with a blade 42 and mounted on a pivot rod 43, which is pivoted upwardly and downwardly to move arm 41 upwardly or downwardly in accordance with the position and longiytudinal extent of the slit.

From the slitting roll 38, strip S passes around a back- 4 ing roll 44, provided with a longitudinal groove 45, which operates in association with a cutting roll 46, provided with a blade 47 extending longitudinally thereof, as in FIG. 7. Blade 47 will be opposite the groove 45 when the blade reaches a position to produce a series of transverse series of slits in the strip S, at equally spaced longitudinal positions along the strip corresponding to the final length of bag desired. The rolls 44 and 46 are rotated in synchronism with heating drum H and the slitting roll 38, as by a gear 48 mounted at each end of roll 44 and in engagement with the respective gear 40 and a gear 49 at each end of roll 46 and in engagement with the respective gear 48, as in FIG. 7. Roll 44 may be mounted on a shaft 50 and roll 46 on a shaft 51, which shafts may be rotatable in suitable bearings mounted at the respective sides of frame F.

From the backing roll 44, strip S passes around a pulling roll 52 which may be provided with an outer layer 53 of rubber or the like to maintain the pull of the roll on the strip S and thereby cause the strip to be pulled around the preceding rolls at a uniform rate. Pulling roll 52 is driven in synchronism with heating drum H and also rolls 25, 38, 44 and 46, which are rotated in the respective directions of the arrows thereon, as by a gear 54 at each end of roll 52 in engagement with the respective gears 48 of roll 44. As shown, the strip S is preferably wrapped around more than one half of the periphery of slitting roll 38, so that the strip will be accurately positioned for engagement with the slitting knives and also preferably is wrapped around more than one half and as great a fraction of the periphery of backing roll 44 as possible, so that the strip will be accurately positioned for engagement with blade 47.

From pulling roll 52, the strip S passes around a tension roll 55 which maintains tension on pulling roll 52 and which also causes the strip to be fed to roll 13 or roll 14 in tangent relation to either. Pulling roll 52 may be mounted on a shaft 56 and tension roll 55 on a shaft 57, which shafts may again be rotatable in suitable bearings mounted on the respective sides of the frame P, such as bearing 58 for shaft 39, as in FIG. 5, supported by a plate 59 extending between two channels or other members of frame F.

The apparatus of FIG. 1 is particularly adapted to produce a series of bags in strip form, such as shown in FIG. 2, in which the last previous bag has been removed from the strip along a transverse series of perforations 60, which are produced by blade 47 of roll 46. It will be noted that strip S shown in FIG. 2 is provided with walls connected together by imperforate lateral edges 61 and 61', but that a strip formed by taking a fiat strip, folding it at the center and sealing one of the edges 61 or 61- may be used. The heat sealing drum H produces a sanitary heat seal 62 at spaced longitudinal positions along strip S, which closes the bottom of each bag separated from the strip. At the top of each bag, the heat sealing drum I-I produces, at spaced longitudinal positions along the strip, a series of connected heat seals including a short, transverse heat seal 63 extending inwardly from edge 61 of the strip in spaced relation to heat seal 62, a longitudinal heat seal 64 extending away from heat seal 62 and parallel to the edge 61 to a transverse heat seal 65 which extends away from the edge 61 to a longitudinal heat seal 66 which may extend parallel to heat seal 64 and in spaced relation therewith to a point adjacent the heat seal 62. The cutting blades, which operate in conjunction with the cutting roll 38, produce a pair of laterally spaced longitudinal slits 67 and 68 respectively inside heat seals 64 and 66 and extending away from heat seal 62 but terminating short of lateral heat seal 65, as well as a pair of relatively short, relatively closely spaced, longitudinal slits 69 extending from a point adjacent heat seal 62 and away from the latter, in the area between heat seal 66 and edge 61. It will be noted that slits 67, 68 and 69 each start at a point at which the transverse series of slits or perforations 60 will later be produced by the blade 47.

When the next bag is separated from strip S, along the series of perforations or slits 60, the portion of the bag between slits 67 and 68, although unsealed at the upper edge of the bag, will not provide an opening into the bag, due to the heat seals 64, 65 and 66. That portion of the bag between heat seal 66 and edge 61 is adapted to form a filling spout, which may be opened readily for filling purposes by separation of the tabs between the slits 69. After the bag has been filled, the filling spout may be closed by heat sealing across the same, as between heat seal 66 and the edge 61', or the filling spout may be folded several times and then held closed by a clamp or other suitable device, slit 68 adjacent heat seal 66 facilitating such folding and clamping. The neck formed between slit 67 and edge 61 is adapted to form a pouring spout, when out ofi to remove heat seal 63. Such a pouring spout may be fitted between a pair of cam actuated clamps, with the bag inverted, after which the neck may be cut 01f to remove the heat seal 63 and the clamps opened and closed to permit discharge of the contents of the bag in controlled increments. Or, the bag may be transported to a place of use, then the end of the neck between edge 61 and slit 67 cut off to remove the heat seal 63, after which the contents of the bag may be emptied through the pouring spout, although the bag is more particularly adapted to be used for dispensing purposes since the contents may be discharged in controlled increments. It will be noted that, due to the flexibility of the walls of the bag, it is not necessary to introduce air into the bag for discharge of the contents, since the bag will collapse through atmospheric pressure as the contents are discharged and atmospheric pressure may always be exerted against fluid in the bag through the flexible walls.

As will be evident, the apparatus of this invention may be utilized in making other forms of bags, such as disclosed in our copending applications Serial No. 721,961 filed March 17, 1958, and Serial No. 810,454 filed May 1, 1959. in particular, the apparatus may be utilized to produce a bag in which the pouring spout is longer and formed in the strip so as to extend along edge 61 of the strip onto a portion of what would otherwise be the next bag, slit 67 again being along the pouring spout but elongated and the series of perforations 60 then extending from slit 67 to edge 61 of the strip. Heat seal 62 then extends to and is connected with heat seal 64, while heat seal 63 is at the opposite end of heat seal 64. Slits 68 and 69 and heat seal 66 may be positioned, as before, but heat seal 65 may extend transversely from heat seal 66, then obliquely to edge 61 of the strip, past the end of the elongated slit 67. A short slit extending inwardly from edge 61, between the new position of heat seals 65 and 63, permits the pouring spout thus formed to be separated from the next bag. The pouring spout will then, of course, be at the opposite end of the bag from the filling spout.

As illustrated in FIGS. 3 and 4, the heat sealing drum H may comprise a cylinder 70 attached, as by welding, to annular end plates 71, one of which is attached to hub 31 mounted on shaft 30 and the other of which may be attached to a hub 31', which is mounted on a hollow shaft 72, with gears 27 mounted on the respective shafts 30 and 72 immediately outside the respective hubs 31 and 31. A pulley 73 may be mounted on shaft 30, so that the heat sealing drum H may be driven by a multiple belt drive from a motor, while shafts 30 and 72 may be rotatably supported by suitable bearings mounted on the opposite sides of frame F. A tube 74 extends inwardly to approximately the center of the drum, through the hollow shaft 72, for supplying cooling Water to the interior of the drum, but the pressure of the water need not be great, since it is necessary only to fill the drum and permit the water to be discharged to flow around the tube 74, within the hollow shaft 72.

At its outer end, shaft 72 may be provided with a stationary stufiing box or connecting valve 75 having an inlet connection 76 for attachment to a line supplying Water to the tube 74 and an outlet connection 77 for receiving the discharge water flowing around the tube 74 within the hollow shaft 72 and connection to a line for removing the same.

On the outside thereof, cylinder 70 may be provided with a pair of heating units 78, disposed in diametrically opposite positions on the drum and adapted to produce the transverse heat seals 62 of FIG. 2, and also with a pair of heating units 79, also disposed in diametrically opposite positions on the cylinder and adapted to produce the heat seals 63, 64, 65 and 66 of FIG. 2. The heating units 78 and 79 may be formed by applying a layer of adhesive insulating material to the surface of the cylinder in a pattern corresponding to the: desired shape of the heating unit, laying a flat resistance strip on each initial layer and then covering each resistance strip with a layer of insulating plastic. A grounded circuit is conveniently employed, so that the end of the resistance strip of each of the heating units 78 and 79, opposite the shaft 72, may be grounded to cylinder 70 and the opposite end connected to an insulated wire 80, which leads from a respective insulated segment of a slip ring 81. As in FIG. 4, slip ring 81 may be divided into two segments, separated by an insulating block 82 on each opposite side of the slip ring. Current may be supplied to the heating units and to wires by a conventional brush adapted to engage the slip ring-81. As will be evident, current will be supplied to each pair of adjacent heating units 78 and 79 one half of the time only, while a suitable timing mechanism, such as the timing mechanism T of FIG. 5, may be used to restrict further the amount of time that current flows through the respective heating units, in order to regulate the temperature of the heating units to prevent overheat ing the same and consequently overheating the strip when the heat seals are made.

As illustrated in FIGS. 5 and 6, the slitting roll38 may be provided with a narrow groove 84 for each blade 42, adapted to produce the slits 67 and 68 of FIG. 2 and into which the blades may extend when the rod 43 on which the arms 4-1 are mounted is turned slightly 'to cause the blades 42 to move toward roll 38. Blades 42 are normally held away from roll 38 by a leaf spring 85, one end of which is connected to rod 43 by a clamp 86 and the opposite end of which is attached by a clamp 87 to the lower flange of a channel 88, forming a part of the frame F. A cam 89, mounted on shaft 39, is adapted to periodically engage a cam follower 90 mounted on rod 43, so as to turn the rod against the resistance of leaf spring and pivot the arms 41 toward roll 38 and thereby cause blades '42 to cut slits 67 and 68 of FIG. 2 at a position on the strip and for a length corresponding to the high area of cam 89.

Roll 38 may also be provided with a pair of narrow grooves 91 into each of which a blade 92 mounted on an arm 93 may extend in cutting the slits 69 of FIG. 2. Arms 93 are mounted on a pivot rod 94, which is independent of the movement and position of rod 43, with arms 93 and blades 92 again normally held away from roll 38 by a leaf spring 85 attached to rod 94 by a clamp 86 and the opposite end of the leaf spring being secured by a clamp 87 to the lower flange of a channel 88'. Arms 93 and blades 92 are moved toward roll 38 by a cam 95, mounted on shaft 39 and adapted to engage a cam follower 96 mounted on rod 94, so as to produce slits 69 of FIG. 2 at positions and for a length corresponding to the position and extent of the high area of cam 95. Although rod 43 and rod 94 are independent in action, the adjacent ends thereof may be supported for pivotal movement in the outer end of an arm 97 which extends toward rods 43 and 94 from a suitable portion of frame F, such as the channel 10 shown in FIG. 1. 'The outer end of each rod 43 and 94 may extend through the respective channel 88 and 88' for engagement with a bearing block 98' mounted on the respective channel.

As illustrated in FIG. 7, blade 47, installed at one point in the periphery of roll 46, extends from end to end of the roll and is provided with a plurality of spaced, sharp edges adapted to produce the transverse series of slits 60 of FIG. 2. Groove 45, which receives the blade 47 as slits 60 are being cut, extends from end to end of roll 44 and is conveniently narrow enough to permit the series of'slits 60 to be cut with ease. It will be noted that roll 52 of FIG. 1 pulls strip S tightly around roll 44, so that the strip will be stretched tight when blade 47 is cutting each series of slits 60. It will further be noted that the heat sealing drum H is provided with two sets of heating units and that therefore two sets of heat seals will be produced during one rotation of the heat sealing drum. However, the slitting blades 42 and 92 of FIG. are actuated only once for each revolution of roll 38, while cutting blade 47 produces a series of slits 60 in the strip only one for each revolution of roll 44. Thus, the diameter of heat sealing drum H may be exactly twice the diameter of rolls 38 and 44, although the heat sealing drum H and the backing rolls 44 may have any other suitable diameter, as long as the circumference of the drum or roll is equal to or a multiple of the desired distance between successive series of perforations 60, corresponding to the length of the bag to be finally produced. Of course, for slitting purposes, slitting roll 38 may have any diameter, as long as cams 89 and 95 are correctly shaped, although if roll 38 has a circumference equal to the length of bag to be produced, correlation of the movement of the slitting knives with movement of the strip is more readily accomplished. Also, the diameter of roll 38 should be one half the diameter of heat sealing drum H, for timing purposes, as described later.

The shaft 39, or any other driven shaft of the machine, may also be used to drive an adjustable timing device T, which controls the amount of time that the heating units 78 and 79 of FIGS. 3 and 4 are supplied with current. This timing device may be similar to the device disclosed in our U.S. Patent No. 2,865,448, and thus may include, as in FIG. 5, a shaft 100 forming an extension of shaft 39 and journalled at its outer end in a suitable bearing supported by an outer plate 101. Outer plate 161 may be supported by a series of rods 102 and 103 from an inner plate 104, in turn mounted on the stationary housing of bearing 58 or attached to a suitable part of frame F. The upper rods 1492 provide a slide for a carriage or adjustable arm 105 which may be moved to any selected position by turning a lead screw 1%, which threadedly engages arm 104, through a handle 107. A switch 108, which may be connected in the circuit of a relay controlling the supply of current to the brush which engages slip ring 81 of FIGS. 3 and 4 is mounted on the underside of arm 195 and is provided with a depending, spring returned actuating lever 109, which clears shaft 100. The switch 108 is normally closed or open, as desired, but is moved to the opposite position upon pressure against lever 109 and returned to initial position when the pressure is released. Pressure against lever 109 is provided by a sleeve 111) having a. spiral edge 111 and therefore a circumferential extent which corresponds to the longitudinal position thereon, while sleeve 110' rotates with shaft 100 and may be attached thereto by a coupling 112. As will be evident, by shifting ar-m 105 to various longitudinal positions along sleeve 110, the amount of time during which pressure will be exerted against switch lever 109 may be adjusted as desired. Assuming switch 108 to be normally open, it will be closed as long as sleeve 110 engages lever 109 and the proportion of each revolution which this will consume will be dependent on the longitudinal position of arm 105. Thus, when arm 105 is adjusted inwardly, the time will increase and when adjusted outwardly, the time will decrease. As will be evident, since heating drum H and slitting roll 38 are driven in synchronism, but heat sealing drum H has twice the diameter of roll 38, shaft 39 will rotate at twice the speed of the shafts for heat sealing drum H, so that the timing device T, which will go through one complete cycle for each revolution of shafts 39 and 100, will thus cause the same time periods of current flow to be produced for each of the two heating units of the heat sealing drum, since it will pass through two cycles for each revolution of drum H.

As illustrated in FIG. 8, the various rolls and drums may be driven by a motor 125, which may be mounted at a lower position within frame F and also may be provided with an integral speed reducer, so as to drive a multiple belt pulley 126 at a suitable reduced speed. Pulley 126, in turn, drives pulley 75 through a series of belts 127, while the gears on heat sealing drum H, previously described, drive both the feed roll 25 and the splitting roll 38 at the same peripheral speed as the heat sealing drum H. In turn, the gears on slitting roll 38, through engagement with the gears on the backing roll 44, drivethe backing roll 44 and cutting roll 46 at the same peripheral speed, while gears 48, in turn, drive the pulling roll 52 at the same peripheral speed. Shafts17 and 17 for the final or winding rolls, may be driven through a chain 128 and a chain 129, respectively, which engage a dual sprocket 13!} mounted on the outer end of shaft 51 for the cutting roll 46. Chain 128 engages a sprocket 131 mounted on shaft 17, as well as a takeup pinion 132 mounted on the frame F to adjust the tension of chain 128. Similarly, chain 129 engages a sprocket 133 mounted on shaft 17', as well as a takeup pinion 134, also mounted on frame F and adapted to adjust the tension of chain 129. It will be understood, of course, that the various drums and rolls may be rotated insynchronism in any other desired manner, although it willbe noted that by driving the various rolls through a pair of gears, backlash is minimized.

In order to permit readier inspection at any desired time, the bags may be separated from the strip as the strip leaves the machine and collected in a stack instead of in a roll. For this purpose, the alternative construction shown in FIG. 9 may be utilized, in which the strip, instead of being fed onto a final roll 13 or 14, is fed from roll 55 past a separating roll provided with a rounded projection 116 and mounted for rotation adjacent a con veyor belt 117 moving around rolls 118 and 119. The inner end of conveyor belt 117 extends to a position to receive the strip S, such as in engagement with roll 55, while the projection 116, each time it engages the strip, will tend to push the leading portion of the strip ahead, thus separating the bag engaged from the remainder of the strip, since the increased radius at the projection 116 provides a higher peripheral speed. Thus, the bags B will be separated from the strip and pass individually along the conveyor belt for discharge onto a stack or other desired disposition.

As will be evident, in order to produce the alternative bag constructed and described previously, and shown in our copending application Serial No. 810,454, filed May .1, 1959, it is necessary only to alter the heating units 78 .and 79 to provide the desired heat seals, to terminate the blade 47 short of one edge of drum 46 and to provide an additional, relatively short, cutting blade at a corresponding longitudinal position but spaced radially from blade 47, with a short groove in the backing drum 44 to are commodate the additional short cutting blade. Also, it may be necessary to provide separate cams and associated mechanism for operating the respective blades 42 so that they will cut slits of different lengths. However, it will be evident to those skilled in the art that these changes may be readily made. Also, other specific bag constructions may be made by simple alterations in the heating units, transverse cutting blade or blades and the knives which produce longitudinal slits.

which the strip passes, longitudinal slits of any desired extent and relation may be produced. By driving the various rolls and drums in synchronism, cuts or slits, although made later, may be positioned accurately with respect to the heat seals. Since the various drums and rolls may be rotated at a substantial speed, the bags may be produced quickly and economically. Thus, the apparatus of this invention is particularly adapted to produce a series of bags, connected together in strip form, fro flexible orpliable, heat scalable material.

Although a preferred embodiment of this invention has been illustrated and described and certain changes indicated, it will be understood that other embodiments may exist and other changes may be made, all without departing from the spirit and scope of this invention.

What is claimed is:

1. Apparatus for making bags of flexible, heat scalable material from a strip of said material in flat form having opposed walls in abutting relation and connected at the lateral edges, comprising a rotating cylindrical drum provided with heating units having a positionand extent on said drum corresponding to heat seals joining said walls to be produced for at least one bag; means for moving said strip around said drum and into engagement with said heating units; means for producing at least one longitudinal slit in said strip of a predetermined extent and at spaced longitudinal positions along said strip corresponding to the length of a bag; and means for producing a transversely extending series of perforations in said strip at spaced positions along said strip corresponding to the length of a bag.

2. Apparatus for making bags, as defined in claim 1, wherein each of said slit producing means and said perforation producing means include a roll around which said strip passes; and means for rotating each said roll in synchronism with said heat sealing drum.

3. Apparatus for making bags, as defined in claim 2, wherein said means for rotating said rolls in synchronism with said drum includes a pair of gears rotatable with said drum and a pair of gears for rotating one of said rolls and in engagement with said drum gears, the other of said rolls being driven by a pair of gears from said gears of said one roll.

4. Apparatus for making bags, as defined in claim 1,

wherein said heating units on said drum are electrically operated; means for supplying electricity to said heating units; and timing means for controlling the supply of current to said heating units.

5. Apparatus for making bags, as defined in claim 1, wherein said means for producing at least one longitudinal slit in said strip includes a roll around which said strip passes; at least one slitting blade movable toward and away from said roll; and means for periodically moving said blade toward said roll and into engagement with said strip.

6. Apparatus for making bags, as defined in claim 1, wherein said means for producing a transversely extending series of perforations includes a rotatable backing roll provided with a longitudinally extending groove; means for causing said strip to pass around said backing roll; a rotatable cutting roll having a longitudinal blade extending outwardly from said roll and provided with a series of spaced, sharp edges; the axis of said cutting roll being parallel to the axis of said backing roll and said cutting roll being disposed in tangent relation to said backing 10 roll; with said groove disposed at a radial position corre sponding to the radial position of said blade so that said groove will accommodate the sharp edges of said blade when said blade engages said strip; and means for rotating said backing roll and cutting roll at the same peripheral speed.

7. Apparatus for making bags, as defined in claim'l, wherein said heating units are electrically operated and said drum is hollow; and including means for supplying a cooling fluid to the interior of said drum.

8. Apparatus for making bags, as defined in claim 1, including a belt for pressing said strip against saiddrum and said heating unit over at least one-half of the periphcry of said drum; and rolls for supporting a portion of said belt in engagement with said strip and the remainder of said belt as a loop spaced from said drum.

9. Apparatus for making bags, as defined in claim 1, including a series of rolls for straightening said strip prior to engagement with said drum, said rolls being disposed with their axes in substantially parallel relation and said strip passing around said rolls in alternating relationJ.

10. Apparatus for making bags, as defined in claim 1,

wherein said slitproducing means is adapted to produce a plurality ,of slits .in each bag .and comprises a roll around which said strip passes and provided with at least .tWo circumf'ere'ntially extending, longitudinally spaced slots at positions corresponding to said slits; a pivotal rod mounted in spaced, parallel relation with respect to the surface of said roll; a series of arms mounted on said roll and movable toward and away from the surface of said roll as said rod pivots; a cutting blade mounted'on each arm adapted to produce a slit in said strip upon-engagement'with said strip; and cam means for periodically pivoting said rod so as to move said blades into engagement with said strip for a predetermined period of time.

11. Apparatus for making bags, as defined in claim 10,

including resilient means for holding said arm normally away from saidroll.

12. Apparatus for making bags of flexible heat scalable material from a strip of saidmaterial in flat form having opposed walls in abutting relation and connected at the lateral edges, comprising a framework having spaced sides and supports for bearings and the like on said sides, in-

cluding at least one set of bearings at one end of said framework for supporting a feed roll of said strip in coil form; a series of at least three rotatable straightening rolls extending between said sides in parallel relation for straightening said strip; a hollow drum mounted for rotation between said sides and provided with heating units having a position on said drum corresponding to the heat .seals joining said Walls to be produced for at least one bag; a feed roll mounted for rotation abutting said drum and in a position such that said strip passes around said feed roll in moving from said straightening rolls to said drum; an endless belt for pressing said strip against the surface of said drum and heating units over at least one half the periphery of said drum; a series of rotatable rolls for supporting said belt, two of said rolls being disposed in juxtaposition to said drum on opposite sides thereof and the remainder of said rolls being spaced from said drum; a rotatable slitting roll abutting said drum, said strip passing around said slitting roll as it leaves said drum; a series of knives for producing longitudinal slits in said bag of a predetermined extent and at spaced longitudinal positions corresponding to the length of a bag, said slitting roll being provided with circumferential grooves corresponding to the position of said knives; means for moving said knives toward and away from said strip as it passes around said slitting roll; a rotatable backing roll around which said strip passes as said strip leaves said slitting roll, said backing roll being provided with a longitudinal groove; a rotatable cutting roll disposed in abutting relation to said slitting roll and provided with a longitudinal blade extending outwardly therefrom and provided with a series of spaced, sharp edges rerdprednein a transversely extending series of perforations in said strip at spaced longitudinal "positions corresponding to the length of a bag, said groove of said backing roll being disposed at a radial position corresponding to the radial position of said blade so that said groove will accommodate the sharp edges of said blade when said blade engages said strip; a rotatable pulling roll around which said strip passes when it leaves said backing roll; an idler roll around which said strip passes after it leaves said pulling roll; at least one support at the opposite end of said frame for a hub on which said strip may be wound after said strip leaves said idler roll; and means for driving said heating drum, said feed roll, said slitting roll, said backing roll, said cutting roll and said pulling roll in synchro'nism.

13. Apparatus for making bags, as defined in claim 12, including means for supporting alternative supply rolls at one end of said framework and alternative receiving rolls at the opposite end of said framework.

14. Apparatus for making bags, as defined in claim 12, wherein said heating units are electrically operated; and including rotatable timing means for controlling the supply of current to said heating units; and means for driving said timing means in synchronis'm with said heating druml 15. Apparatus for making bags, as defined in claim 12, wherein said drive means includes a pair of gears mounted at each end of said drum; a gear mounted at each end of said feed roll and in engagement with the respective drum gears; a gear mounted at each end of said slitting roll and in engagement with the respective drum gears; a gear mounted at each end of said backing roll and in engagement with the respective slitting roll gears; a gear mounted at each end of said pulling roll and in engagement with the respective backing roll gears; a gear at each end of said cutting roll and in engagement with the respective backing roll gears; and means for driving the shaft for said strip receiving roll from one of said rolls provided with said gears.

16. Apparatus for making bags, as defined in claim 1; wherein said sealing drum comprises a shaft at each end thereof and a hub mounted on the inner end of each shaft, one said shaft being hollow; a pulley for rotating said drum mounted on the shaft opposite said hollow shaft; an inner end plate mounted on each said hub; a hollow cylindrical shell extending between and attached to the peripheries of said end plates; a tube extending through said hollow shaft into the interior of said drum; and a sealing connection at the outer end of said hollow shaft provided with an inlet attachment for supplying cooling water to said inner tube and an outlet attachment for discharging Water flowing around said inner tube and within said hollow shaft, said hollow shaft being rotatable with respect to said connection.

17. Apparatus for making bags, as defined in claim 1,

amazes 12 wherein said heating units are electrically operated and are dis osed on opposite sides of said drum and adapted to produce heat seals for two bags in spacedlongitudinal positions along said strip during one revolution of said drum; said drum is hollow and is formed of metal, one end of each heating unit being grounded to the outside of said drum; including insulated wires connected to the opposite ends of the respective heating unit; a slip ring divided into two segments and rotatable with said drum, the opposite ends of said insulated wires connecting one set of heating units to one segment and the other set of heating units to the opposite segment of said slip ring; and a stationary brush for supplying current to said slip ring. 18. Apparatus for making bags, as defined in claim 1, wherein said slit producing means comprises a roll having at least one circumferentially extending slot around its periphery in one longitudinal position of said roll and at least one circurnferent'ially extending slot in a second longitudinal portion of s'aid 'roll; a rotatable shaft for said roll; a first rod disposing in spaced parallel relation to said one longitudinal portion of said roll; a second rod disposed in spaced parallel relation to said second longitudinal portion of said roll and 'in axial alignment with said first rod, said first rod extending past one end of said roll and said second rod extending past the opposite end of said roll; at least one arm mounted on said first rod, each'ar'm being opposite a slot in said first longitudin'al portion of said roll; at least one arm mounted on said second rod, each arm being opposite a slot in said second longitudinal portion of said roll; a knife carried by each arm on each rod for producing a slit in said roll upon engagement therewith; means for supporting the outer end of each rod for pivotal movement; common means for supporting the inner ends of said rods for pivotal movement; separate springs connected to said rods for holding said rods normally in a position with the knives supported thereby away from said strip; first and second cams mounted on said shaft at the respective ends of said roll; and a cam follower mounted on each said rod for engagement with the respective cam at periodic intervals to move the knives supported by the respective rod into engagement with said strip, said cams being constructed so that the knives supported by said first rod will engage said strip for a lesser period of time than the knives supported by the said secondsrod.

References Cited in the file of this patent UNITED STATES PATENTS 2,525,139 Ligon Oct. 10, 1950 2,680,471 Mercer June 8, 1954 FOREIGN PATENTS 631,440 Great Britain a;.--a Nov. 2, 1949 690,614 Great Britain ..'..;:..-'..--*-\5 Apr. 22, 1953 

